CN116979779A

CN116979779A - Vibration actuator and electrical device

Info

Publication number: CN116979779A
Application number: CN202310469507.0A
Authority: CN
Inventors: 下村重幸; 荻原裕树; 木下洋辅
Original assignee: MinebeaMitsumi Inc
Current assignee: MinebeaMitsumi Inc
Priority date: 2022-04-28
Filing date: 2023-04-27
Publication date: 2023-10-31
Also published as: EP4270746A1; JP2023163729A; US20240079942A1

Abstract

The present invention relates to a vibration actuator and an electrical apparatus. A vibration actuator (1) of the present invention comprises: a movable body (20) having a columnar magnet (21); and a fixed body (40), wherein the fixed body (40) is provided with a coil (60) and a main body part (42), the main body part (42) is provided with an inner peripheral surface (42 a) surrounding the movable body (20) with a gap (G) between the inner side of the coil (60) and the outer peripheral surface of the movable body (20), the main body part (42) supports the movable body (20) by means of elastic supporting parts (81, 82) in a mode that the movable body (20) can vibrate in the axial direction of the movable body (20), and the vibration actuator (1) is configured in such a way that the gap (G) generates fluid flow in a direction opposite to the moving direction of the movable body (20) and generates pipeline resistance for the fluid.

Description

Vibration actuator and electrical device

Technical Field

The present invention relates to a vibration actuator and an electrical device provided with the vibration actuator.

Background

Conventionally, a vibration actuator as a vibration source is mounted in an electronic device having a vibration function as an electric device. The electronic device can impart a stimulus, notify an incoming call, or improve a sense of operation, a sense of reality, or the like by driving the vibration actuator to transmit vibration to the user and causing the body to feel the vibration. The electronic devices are mainly handheld electric devices including portable game terminals, controllers (game pads) of stationary game machines, mobile communication terminals such as mobile phones and smartphones, and mobile information terminals such as tablet computers. In addition, the vibration actuator may be mounted on a wearable terminal or the like attached to clothing, an arm, or the like.

As a vibration actuator of a miniaturized structure to be mounted on a mobile device, for example, a vibration actuator for a pager or the like as shown in patent document 1 is known.

In this vibration actuator, a pair of plate-like elastic bodies are arranged so as to face each other, and the plate-like elastic bodies are supported by the opening edge of a cylindrical frame. In this vibration actuator, a yoke to which a magnet is attached is fixed to a raised central portion of one of a pair of plate-like elastic bodies, which is a spiral shape, and the yoke is supported in a housing.

The yoke and the magnet form an annular magnetic field generator, and a coil is disposed in a state of being attached to the other plate-like elastic body in the magnetic field of the magnetic field generator. By applying currents of different frequencies to the coils in a switching manner by the oscillating circuit, the pair of plate-like elastic bodies selectively resonate to generate vibrations, and the yoke vibrates in the frame body in the direction of the center line of the frame body.

In this vibration actuator, the distance between the magnet and the coil and the distance between the yoke and the coil are made larger than the distance between the yoke and the inner peripheral wall of the housing. Therefore, when the magnet yoke collides with the inner peripheral wall of the frame body, the magnet yoke and the magnet are not contacted with the coil, and the damage of the coil is prevented.

Prior art literature

Patent literature

Patent document 1: japanese patent No. 3748637.

Disclosure of Invention

Problems to be solved by the invention

However, the vibration actuator as the vibration generator is miniaturized with miniaturization of the mounted product, while ensuring high output.

In this structure for realizing miniaturization, vibration is preferably generated in a wide frequency band according to the environment used.

The present invention has been made in view of such a point, and an object thereof is to provide a vibration actuator and an electrical device which can be miniaturized and which can generate an appropriate vibration output in a wide frequency band according to the environment or the like used.

Solution to the problem

One mode of the vibration actuator of the present invention includes:

a movable body having a columnar magnet; and

a fixed body having a coil and a main body portion that surrounds an inner peripheral surface of the movable body with a gap between the main body portion and the outer peripheral surface of the movable body on an inner side of the coil, and that supports the movable body via an elastic support portion so that the movable body can vibrate in an axial direction of the movable body,

the vibration actuator is configured to generate a flow of fluid in a direction opposite to a moving direction of the movable body in the gap, and to generate a line resistance against the fluid.

One form of the electrical device of the present invention is a handheld or wearable electrical device,

the vibration actuator having the above structure is mounted on a contact portion to be brought into contact with a user.

Effects of the invention

According to the present invention, it is possible to generate an appropriate vibration output in a wide frequency band according to the environment or the like used while achieving miniaturization.

Drawings

Fig. 1 is an external perspective view of a vibration actuator according to an embodiment of the present invention as seen from the front side.

Fig. 2 is a top view of a vibration actuator.

Fig. 3 is a cross-sectional view taken along line A-A of fig. 2.

Fig. 4 is a diagram showing a state in which the housing and the driving unit inside the housing are separated in the vibration actuator.

Fig. 5 is a view showing an outer surface of the coil assembly after the outer yoke is removed from the coil assembly in the driving unit.

Fig. 6 is an exploded perspective view showing the coil assembly and the movable body.

Fig. 7 is a perspective view showing the movable body and the elastic support portion.

Fig. 8 is an exploded perspective view of the movable body and the elastic supporting portion.

Fig. 9 is an exploded perspective view of the coil assembly.

Fig. 10 is a perspective view showing the internal structure of the housing.

Fig. 11 is a perspective view showing the back surface of the cover.

Fig. 12 is a partially enlarged sectional view for explaining the gap and the movable space.

Fig. 13 is a left side view of the vibration actuator for explaining the wire holding portion.

Fig. 14A and 14B are diagrams for explaining the wire holding portion.

Fig. 15 is a diagram for explaining a modification of the wire holding portion.

Fig. 16 is a diagram schematically showing a magnetic circuit structure of the vibration actuator.

Fig. 17A and 17B are diagrams for explaining a main body of the vibration actuator.

Fig. 18 is a diagram for explaining the difference in resonance frequency caused by the presence or absence of air damping in the vibration actuator.

Fig. 19 is a diagram showing an example in which a vibration actuator is mounted on a game controller.

Fig. 20 is a diagram showing an example in which a vibration actuator is mounted on a mobile terminal.

Description of the reference numerals

1. 204, 205, 206 vibration actuator

10. Shell body

11. Casing body

12. Cover part

15. Driving unit

16. Lead wire

18. Wire holding part

20. Movable body

20a peripheral surface

21. Magnet

21a front face

21b back face

23. A first magnetic yoke

25. A second magnetic yoke

27. 29 hammer part

40. Fixing body

41. Roundabout part

42 coil holding part (Main body part)

42a inner peripheral surface

42b, 42c coil mounting portion

43. Terminal binding part

44. 45-degree clamping protrusion

46. Terminal lead-out part

47. Connecting groove part

50. Outer yoke

51. Yoke body

52. End portion

53. An opening part

60. 61, 62 coil

63. 64 winding wire

81. 82 elastic support portion

88. Attenuation part

112. Peripheral wall part

113. Cut-out part

114. Bottom part

118. 128 step part

122. Top surface portion

122b recess

124. Sagging portion

127. Engagement concave portion

180. Wire holding part

182. Wire insertion part

184. Wire fixing part

186. Clamping and hanging part

187. Adhesive agent

201. Communication unit

202. Processing unit

203. Drive control unit

232. 252 groove part

272. 292 hammer main body

274. 294 spring fixing part

276. 296 chamfer portion

420. Concave portion

422. Cylindrical body part

426. Central flange portion

426a peripheral portion

427. 428 end flange portion

427a, 428a open end

432. Aqueduct

802. Inner peripheral portion

802a connecting hole

804. Deformation arm

806. Peripheral portion

808. Groove part

Detailed Description

Embodiments of the present invention will be described in detail below with reference to the accompanying drawings.

[ Integrated Structure of vibration actuator ]

Fig. 1 is an external perspective view of a vibration actuator according to an embodiment of the present invention as seen from the front side, fig. 2 is a plan view of the vibration actuator, and fig. 3 is a sectional view taken along line A-A of fig. 2. Fig. 4 is a diagram showing a state in which the housing and the driving unit inside the housing are separated in the vibration actuator. Fig. 5 is a view showing an outer surface of the coil assembly after the outer yoke is removed from the coil assembly in the driving unit, and fig. 6 is an exploded perspective view showing the coil assembly and the movable body.

In the present embodiment, "upper" and "lower" are added for the convenience of understanding, and refer to one or the other of the movable body in the vibration actuator in the axial direction, that is, in the vibration direction. That is, when mounted on an electrical device (for example, the electronic device shown in fig. 19 and 20), the vibration actuator may be reversed in vertical direction or may be left and right. The lead shown in fig. 1 is not illustrated in fig. 3 to 6 and 9 for convenience.

The vibration actuator 1 is mounted as a vibration source in an electronic device such as a portable game terminal device as an electric device (see fig. 19), and realizes a vibration function of the electronic device. The electronic device also includes a mobile device such as a smart phone (see fig. 20). The vibration actuator 1 is mounted on each device such as a portable game terminal device and a mobile device, and is driven to vibrate to notify a user of an incoming call, and to give an operational feeling and a sense of realism.

As shown in fig. 1, the vibration actuator 1 is a vibrator having a columnar casing 10, and is formed in a columnar shape, for example.

In the present embodiment, as shown in fig. 1 to 4, the housing 10 is a hollow cylinder composed of a plurality of housing parts, including a housing main body 11 as a first housing and a cover 12 as a second housing. In addition, a vent hole for communicating the outside with the inside is not provided in the case 10. The detailed description of the case 10 will be described later.

As shown in fig. 1 to 4, the vibration actuator 1 is configured by accommodating a driving unit 15 having a movable body 20 that vibrates in a housing 10. The vibration actuator 1 itself functions as a vibrator by the movable body 20 being movable in the axial direction of the movable body 20 as the vibration direction.

In the present embodiment, the drive unit 15 is cylindrical as a whole, and its center axis (not shown) is parallel to or coaxial with the center axis (not shown) of the housing 10 which is also cylindrical. In the present embodiment, the vibration direction of the movable body 20 is a linear direction including an F direction and a-F direction (see fig. 16) extending in the direction of the central axis of the cylindrical driving unit 15.

The vibration actuator 1 includes: the movable body 20 having a magnet 21, a first yoke 23, a second yoke 25, and weights (a first weight 27 and a second weight 29); a fixed body 40 having a coil (a pair of coils 61, 62), a coil holding portion 42, and a housing; and plate-like elastic support portions 81, 82.

As shown in fig. 3, the vibration actuator 1 has an annular gap G (see fig. 3, hereinafter, simply referred to as "gap G") between the inner peripheral surface 42a of the coil holding portion 42 of the fixed body 40 and the outer peripheral surface 20a of the movable body 20. In the vibration actuator 1, the movable body 20 is supported by the fixed body 40 via the elastic support portions 81, 82 so as to be capable of vibrating in the axial direction. In the vibration actuator 1, the movable body 20 is included in the driving unit 15 together with the coil holding portion 42, and the driving unit 15 is housed in the case 10.

The vibration actuator 1 is configured such that a flow of fluid in a direction opposite to a moving direction of the movable body 20 is generated in the gap G, and a line resistance is generated with respect to the fluid. The details of the gap G will be described later together with a description of the line resistance.

The driving unit 15 shown in fig. 3 to 6 includes: the coil holding portion 42 constitutes a coil assembly as a part of the fixed body together with the coils 61, 62; an outer yoke 50; a movable body 20; elastic support portions 81, 82.

In the driving unit 15, the movable body 20 disposed with a gap G between the movable body and the inner peripheral surface 42a of the coil holding portion 42 is supported in the coil holding portion 42 by elastic support portions 81 and 82 disposed so as to face each other with a gap therebetween in the axial direction (vibration direction), so that the movable body 20 is supported in a state suspended from the coil holding portion 42 so as to be reciprocatingly movable in the vibration direction.

The driving unit 15 is connected to an external device via a terminal binding portion (connection portion) 43 exposed on the outer peripheral surface (outer peripheral surface of the coil holding portion 42), and receives power from the external device.

As shown in fig. 3 to 6, the coil assembly is a cylindrical body that forms a part of the fixed body together with the outer yoke 50, and the movable body 20 is housed in a freely movable manner inside the coil assembly via the elastic support portions 81 and 82.

< movable body 20>

As shown in fig. 3, the movable body 20 is disposed radially inside the tubular coil holding portion 42 of the fixed body 40 with a gap therebetween. The movable body 20 is columnar, and is connected to the inner peripheral portions of the elastic supporting portions 81, 82 at both end portions (upper end portion and lower end portion) spaced apart in the axial direction, that is, in the vibration direction. The elastic support portions 81 and 82 are attached so as to cover the two openings (opening end portions 427a and 428 a) of the tubular coil holding portion 42.

The movable body 20 is supported so as to be reciprocally movable in the axial direction along the inner peripheral surface 42a of the coil holding portion 42. The movable body 20 may have any shape as long as it is columnar and has a horizontal cross-sectional shape. Preferably, the movable body 20 is formed in a cylindrical shape or a polygonal shape having a substantially cylindrical shape, for example, and is easily formed in a shape having a constant width over the entire circumference with respect to the gap between the inner peripheral surface 42a of the coil holding portion 42 (the tubular body portion 422). The outer peripheral surface 20a of the movable body 20 has a length protruding to both sides in the axial direction beyond the inner peripheral surface 42a of the coil holding portion 42 in the entire movable region of the movable body 20, and the occurrence of the line resistance as the air damping effect is held in the entire movable region of the movable body 20.

Fig. 7 is a perspective view of the movable body to which the elastic support portion is attached, and fig. 8 is an exploded perspective view of the movable body to which the elastic support portion is attached.

As shown in fig. 6 to 8, the movable body 20 includes: the magnet 21, a pair of weights (weights 27, 29), and a pair of movable body yokes (first yoke 23 and second yoke 25) disposed between the magnet 21 and the pair of weights 27, 29.

As shown in fig. 3, 7, and 8, in the present embodiment, a magnet 21 is disposed in the movable body 20 at the center in the axial direction of the movable body 20, that is, in the vibration direction, that is, at the center of the movable body 20. On both sides (front surface 21a side and rear surface 21b side shown in fig. 8, in the vertical direction in the drawings) in the vibration direction of the magnet 21, a first yoke 23 and a second yoke 25, a weight 27, and a weight 29 are arranged symmetrically about the magnet 21, respectively. Specifically, on both sides of the magnet 21 in the vibration direction, a first yoke 23 and a weight 27, and a second yoke 25 and a weight 29 are laminated in this order, respectively.

In the movable body 20, the outer diameters of the magnet 21, the first yoke 23, the second yoke 25, the weight 27, and the weight 29 are equal to or substantially equal to each other. The magnet 21, the first yoke 23, the second yoke 25, the weight 27, and the weight 29 constitute an outer circumferential surface 20a that is flat in the axial direction. Thus, the outer peripheral surface 20a of the movable body 20 is flush or substantially flush, and is a flat peripheral surface free of irregularities.

Both ends (weights 27, 29) of the movable body 20 in the vibration direction are located outside the both ends in the vibration direction in the inner peripheral surface 42a of the fixed portion 40 (coil holding portion 42) when not driven.

Further, when both sides of the movable body 20 in the vibration direction are located at the maximum amplitude positions (see fig. 17A and 17B), the weight 27 and 29 of one of the weight 27 and the weight 29 are located at positions separated from the range facing the outer yoke 50 in the radial direction. The weight 27 and the weight 29 are joined to the first yoke 23 and the second yoke 25 stacked on the magnet 21 in the axial direction of the magnet so that the outer peripheral surface 20a of the movable body 20 protrudes on both sides in the vibration direction (axial direction) over the entire movable region of the movable body 20 than the inner peripheral surface 42a of the coil holding portion 42 of the fixed body 40.

In the movable body 20, the substantially flat outer surface of the outer surface 20a having no irregularities is specifically the outer surface of a part (the hammer bodies 272, 292) of the magnet 21, the first yoke 23, the second yoke 25, and the weights 27, 29. Even in the drive reference position and the maximum amplitude position, the outer peripheral surfaces of the magnets 21, the first yoke 23, the second yoke 25, and parts of the weights 27 and 29 (the weight bodies 272 and 292) are opposed to each other with a predetermined interval therebetween inside the inner peripheral surface 42a of the coil holding portion 42. The driving reference position is a position to be a reference when the movable body 20 moves in the vibration direction, and is, for example, a position located at a center portion right in the vibration direction in the non-energized state. As shown in fig. 3, the movable body 20 has a stroke length of t×2, which is a length T from the position K to the inner peripheral surface 42a and a length T in a direction from the position K to the inner peripheral surface 42a separated by the length T.

< magnet 21>

As shown in fig. 7 to 8, the magnet 21 is a solid columnar body (also including a plate shape) magnetized in the vibration direction. For example, in the magnet 21, the front face 21a and the rear face 21b spaced apart in the vibration direction have different polarities, respectively. In the present embodiment, the magnet 21 is formed in a cylindrical shape (may also be referred to as a "disk shape") having a longer diameter (width) than the length (height) in the vibration direction. The magnet 21 may be processed with a recess or the like, but if it is a solid cylinder, it can be manufactured at a lower cost than a magnet processed with a recess or the like. The magnet 21 is, for example, a neodymium sintered magnet. As a process for the magnet 21, a groove may be provided in which an adhesive is stored when the front surface 21a and the rear surface 21b are bonded to each other by adhesion or the like between the first yoke 23 and the second yoke 25.

The magnet 21 is disposed at a position spaced apart from the coils (a pair of coils 61 and 62) (described later) held by the coil holding portion 42, and radially inward of the coils (a pair of coils 61 and 62). Here, the "radial direction" is also a direction orthogonal to the axial direction (vibration direction) of the coil (the pair of coils 61, 62). In other words, the magnet 21 is disposed to face the center position in the vibration direction on the radially outer side of the inner peripheral surface 42a of the coil holding portion 42. The pair of coils 61 and 62 is hereinafter also referred to as "coils 61 and 62".

The radial interval is an interval between the coils 61 and 62 and the magnet 21 in a state where the cylindrical body portion 422 around which the coils 61 and 62 are wound exists between the coils 61 and 62 and the magnet 21, on the radial inner side of the coils 61 and 62. The interval is set to be an interval at which the movable body 20 can move in the vibration direction of the movable body 20 so as not to bring the coils 61 and 62 into contact with the magnet 21.

The magnet 21 may have a shape other than a solid column such as a cylinder, a plate, or the like as long as it is disposed inside the coils 61, 62 with the two magnetization surfaces facing in the extending direction of the axes of the coils 61, 62, respectively. Further, it is preferable that the center in the axial direction of the magnet 21 coincides with the center in the axial direction of the movable body 20.

< first yoke 23 and second yoke 25>

The first yoke 23 and the second yoke 25 are magnetic materials and are disposed on the front surface 21a and the rear surface 21b of the magnet 21, respectively, so that the magnetic path of the magnetic flux of the magnet 21 is made efficient. The first yoke 23 and the second yoke 25 are formed in a columnar shape (may be plate-like) having a thickness in the axial direction, and have the same outer diameter as the magnet 21.

The first yoke 23 and the second yoke 25 are columnar, for example, are columnar (may also be referred to as a "disk shape") having the same diameter as the magnet 21, and each have an outer peripheral surface flush with the outer peripheral surface of the magnet 21. The first yoke 23 and the second yoke 25 are fixed to the front and rear surfaces of the magnet 21, and the outer peripheral surfaces thereof constitute a flat outer peripheral surface 20a of the movable body 20 together with the outer peripheral surface of the magnet 21 and a part of the weights 27, 29.

The first yoke 23 and the second yoke 25 constitute a magnetic circuit of the vibration actuator 1 together with the magnet 21, the coil (the pair of coils 61, 62) and the outer yoke 50. The first yoke 23 and the second yoke 25 concentrate the magnetic flux of the magnet 21, pass the magnetic flux efficiently without leakage, and effectively distribute the magnetic flux flowing between the magnet 21 and the coils (the pair of coils 61 and 62). The first yoke 23 and the second yoke 25 are preferably formed of a magnetic material made of metal such as SECC (galvanized steel sheet (bonderized steel plate)).

The first yoke 23 and the second yoke 25 function as a part of the magnetic circuit, and also function as a main body portion of the movable body 20 and as a counterweight in the movable body 20. Further, when the weights 27 and 29 having the same outer diameters are joined to each other, the first yoke 23 and the second yoke 25 function to position the weights 27 and 29 with respect to the magnet 21 by aligning the outer diameters of the weights.

In the present embodiment, the first yoke 23 and the second yoke 25 are identical members formed in the same manner, and are symmetrically disposed on the front surface 21a and the rear surface 21b (upper surface and lower surface) of the magnet 21 with the magnet 21 interposed therebetween, centering on the magnet 21. The first yoke 23 and the second yoke 25 may be fixed by being attracted to the magnet 21, and may be fixed to the magnet 21 by a thermosetting adhesive such as epoxy or an anaerobic adhesive, for example. The first yoke 23 and the second yoke 25 are fixed to the weights 27, 29 by the adhesive.

A groove (not shown) and a groove 252, which are reservoirs for storing adhesive or welding materials, are provided in the joint between the magnet 21 and each of the first yoke 23 and the second yoke 25. A groove 232 and a groove (not shown) as an accumulation portion for accumulating an adhesive or a welding material are provided in each of the joint portion between the first yoke 23 and the weight portion 27 and the joint portion between the second yoke 25 and the weight portion 29.

The groove portions 232 and 252 are provided on outer peripheral portions of front and rear surfaces of the first yoke 23 and the second yoke 25, respectively, in the circumferential direction. The grooves 232 and 252 are formed so that an adhesive or a welding material for joining the members to be laminated and fixed with the first yoke 23 and the second yoke 25 is stored so as not to overflow to the outside in the radial direction of the grooves 232 and 252. That is, the adhesive or the welding material does not leak out to the outer peripheral side from the joint portion between the magnet 21 and the first yoke 23 and the second yoke 25, the joint portion between the first yoke 23 and the weight 27, and the joint portion between the second yoke 25 and the weight 29.

That is, when the magnets 21 and the weights 27 and 29 are bonded to the front and rear surfaces of the first and second yokes 23 and 25 with the adhesive interposed therebetween, the grooves 232 and 252 accumulate the adhesive that moves radially outward with the object to be bonded interposed therebetween. Thus, the adhesive does not overflow from the joint portions of the first yoke 23 and the magnet 21, the first yoke 23 and the weight 27, the second yoke 25 and the magnet 21, and the second yoke 25 and the weight 29 to the outer edge side, and the respective members are joined.

Thus, the outer peripheral surface of the movable body 20 formed by the engagement of the magnet 21, the first yoke 23, the second yoke 25, and the weights 27, 29 can be made smooth.

The grooves 232, 252 may be provided on at least one of the surfaces to be joined to each other, or may be provided on the magnet 21 side or the weights 27, 29 side.

The groove portions 232 and 252 may be provided on at least one of the front and rear surfaces of the first yoke 23 and the second yoke 25, respectively. Since the first yoke 23 and the second yoke 25 have the groove portions 232 and 252 on the front and/or rear surfaces, the first yoke 23 and the second yoke 25 can be joined to the magnet 21 and the weights 27 and 29 without setting the orientations thereof. When the first yoke 23 and the second yoke 25 are formed of SECC or the like, the grooves 232 and 252 can be easily formed by press working.

The first yoke 23 and the second yoke 25 are located at positions facing the coils (the pair of coils 61 and 62) in a direction orthogonal to the axial direction of the coils (the pair of coils 61 and 62) on the inner side (the radial inner side) of the coils (the pair of coils 61 and 62) when not vibrating.

Preferably, when the movable body 20 is not vibrating, the first yoke 23 and the second yoke 25 are located at positions facing the centers of the pair of coils 61 and 62 in the vibrating direction, on the inner sides (radially inner sides) of the pair of coils 61 and 62, respectively, in the direction orthogonal to the vibrating direction.

In the present embodiment, it is preferable that the first yoke 23 and the second yoke 25 have the height position of the upper surface of the first yoke 23 on the upper side of the magnet 21 located on the lower side (center side) than the position of the upper end of the upper coil 61. Further, it is preferable that the height position of the lower surface of the second yoke 25 on the lower side of the magnet 21 is located on the upper side (center side) than the position of the lower end of the coil 62 on the lower side. With this configuration, the first yoke 23 and the second yoke 25 together with the magnet 21, the coils 61, 62, and the outer yoke 50 constitute a suitable magnetic circuit with little magnetic leakage and high magnetic efficiency.

< hammer 27, 29>

The weights 27 and 29 are provided on the first yoke 23 and the second yoke 25 joined to the front and rear surfaces of the magnet 21 so as to sandwich the first yoke 23 and the second yoke 25 in the vibration direction (the magnetization direction of the magnet 21), respectively.

The weights 27 and 29 are disposed symmetrically in the vibration direction with respect to the center in the vibration direction in the first yoke 23 and the second yoke 25, respectively, and increase the vibration output of the movable body 20. The weights 27 and 29 are formed in the movable body 20 at both ends in the vibration direction, that is, at both ends at positions spaced apart from the magnet 21 at both sides in the vibration direction.

Preferably, the weights 27, 29 are made of a material having a high specific gravity. The weights 27, 29 are formed of a material having a higher specific gravity than the first yoke 23 and the second yoke 25, for example, copper sintered or the like. Further, the weight parts 27, 29 are preferably made of a specific gravity ratio silicon steel plate (specific gravity of the steel plate is 7.70g/cm ³ ～7.98g/cm ³ ) Equal material height (e.g. a specific gravity of 16g/cm ³ ～19g/cm ³ Left or right), or may be made of tungsten (19.3 g/cm) ³ ) Etc. Accordingly, even when the external dimensions of the movable body 20 are set by design or the like, the mass of the movable body 20 can be relatively easily increased, and a desired vibration output that is sufficient for the user to vibrate in a body sense can be achieved.

The outer diameters of the weights 27 and 29 are the same as or substantially the same as the outer diameters of the first yoke 23 and the second yoke 25.

The weights 27 and 29 have: the hammer bodies 272 and 292 have the same diameter or substantially the same diameter as the outer diameters of the first yoke 23 and the second yoke 25; and spring fixing portions 274 and 294 protruding from the hammer bodies 272 and 292 and connected to the elastic support portions 81 and 82. The hammer bodies 272 and 292 are formed in a columnar shape (may also be referred to as a "plate shape") and have a length in the vibration direction.

The weights 27 and 29 are formed in a cylindrical shape having two end surfaces spaced apart in the vibration direction, and are configured identically, for example, in the same shape. The weights 27 and 29 are fixed to the first yoke 23 or the second yoke 25 at end surfaces (one end surfaces) on the magnet 21 side, and the elastic support portions 81 and 82 are connected to the other end surfaces spaced apart from the magnet 21 side via spring fixing portions 274 and 294, respectively.

Chamfering portions 276 and 296 formed by chamfering are provided at the corners of the other end surfaces of the hammer portions 27 and 29, and spring fixing portions 274 and 294 are provided to protrude from the center portions of the other end surfaces.

The chamfer portions 276 and 296 form sliding portions that receive deformation of the elastic support portions 81 and 82 connected to the spring fixing portions 274 and 294 and extending in the radial direction when the movable body 20 vibrates, and the deformed elastic support portions 81 and 82 are not brought into contact with the movable body 20.

Thus, the movable body 20 can vibrate appropriately, and a high vibration output is ensured while achieving miniaturization of the vibration actuator 1.

Further, if the weights 27 and 29 are made of a non-magnetic material, the expansion of the magnetic circuit structure of the vibration actuator 1 in the vibration direction can be suppressed, and the magnetic circuit can be compactly constructed.

Since the weights 27 and 29 are made of a nonmagnetic material such as copper sintering, which does not affect the magnetic circuit size, the degree of freedom in designing the weights 27 and 29 can be improved in order to obtain desired vibration characteristics of the movable body 20.

The spring fixing portions 274 and 294 fix the movable body 20 to the elastic support portions 81 and 82.

The spring fixing portions 274 and 294 are disposed along the axial center of the hammer main bodies 272 and 292 (the central axis of the movable body 20), and have truncated cone portions and protruding end portions.

The spring fixing portions 274 and 294 constitute both end portions of the movable body in the vibration direction. In the spring fixing portions 274 and 294, protruding end portions are provided protruding from a central portion of the truncated cone portion having a truncated cone shape in cross section, and the protruding end portions are engaged with the inner peripheral portions 802 of the elastic supporting portions 81 and 82, respectively. The protruding end portion has a flange-shaped pressure-bonding section at the tip, and the pressure-bonding section is fixed to the elastic support sections 81, 82 by being pressure-bonded to the inner peripheral section 802. The truncated cone portion may be a cylinder, a polygonal trapezoid, or a polygonal shape, instead of the truncated cone.

The spring fixing portions 274, 294 have an outer diameter smaller than that of the hammer bodies 272, 292. The spring fixing portion 274 is joined to the inner peripheral portion 802, which is an end of the elastic support portion 81, that is, an end of the upper leaf spring on the inner diameter side, which is one end of the movable body 20 in the vibration direction, that is, an end of the upper side of the movable body 20. The spring fixing portion 294 constitutes the other end portion in the vibration direction of the movable body 20, that is, the lower end portion of the movable body 20, and is joined to the inner peripheral portion 802 of the lower leaf spring, which is the elastic support portion 82.

The inner peripheral portions 802, 802 are held between the flange-like distal end portion and the upper surface of the conical portion, and are reliably held by the weights 27, 29, with the spring fixing portions 274, 294 fitted in and joined to the inner peripheral portions 802, 802 of the elastic support portions 81, 82.

The spring fixing portions 274 and 294 fix the flange-shaped distal ends (protruding ends) to the elastic support portions 81 and 82 by crimping or the like. The spring fixing portions 274 and 294 may be joined to the elastic supporting portions 81 and 82 by a method of press-bonding a combination of welding and adhesive bonding.

The spring fixing portions 274 and 294 are disposed in the movable body 20 at positions separated from the magnetic circuit on the movable body side including the magnet 21, the first yoke 23, and the second yoke 25. Accordingly, the arrangement space of the pair of coils 61 and 62 is not limited, that is, the distance between the magnetic circuit (the magnet 21, the first yoke 23, and the second yoke 25) on the movable body side and the pair of coils 61 and 62 is not separated, and the efficiency of electromagnetic conversion is not lowered. This can appropriately increase the weight of the movable body 20, and can realize a high vibration output.

< fixed body 40>

Fig. 9 is an exploded perspective view of the coil assembly.

The fixed body 40 shown in fig. 3 to 6 and 9 accommodates the movable body 20 having the magnet 21 inside the pair of coils 61, 62 in the radial direction with a gap G between the inner peripheral surface 42a and the outer peripheral surface 20a of the movable body 20. The fixed body 40 supports the movable body 20 by means of elastic support portions 81 and 82 so as to be movable in the axial direction of the movable body 20 (in the vibration direction, also in the coil axial direction).

The fixed body 40 has a housing 10, a coil assembly, and an outer yoke 50. The coil assembly includes a coil (a pair of coils 61 and 62) and a coil holding portion 42 for holding the coils 61 and 62. The coil assembly constitutes the driving unit 15 together with the movable body 20, the outer yoke 50, and the elastic support portions 81, 82.

The fixed body 40 may be configured not to include the housing 10 if the coil holding portion 42 that holds the pair of coils 61 and 62 supports the movable body 20 via the elastic support portions 81 and 82 so that the movable body 20 can freely move.

The coil holding portion 42 is a member in which the coil 60 (a pair of coils 61 and 62) is disposed, and is made of a nonmagnetic material. The coil holding portion 42 may be formed in a tubular shape for holding the coils 61 and 62, for example. The coil holding portion 42 is a cylindrical body formed of a resin such as a phenol resin or polybutylene terephthalate (poly butylene terephtalate; PBT). In the present embodiment, the coil holding portion 42 is formed of a material including a phenolic resin such as Bakelite (Bakelite) having high flame retardancy.

Since the coil holding portion 42 is made of a material including a phenolic resin, flame retardancy is improved, and even when electric current flows to the held coil (the pair of coils 61 and 62), heat is generated by joule heat, so that safety during driving can be improved. In addition, since the dimensional accuracy is improved and the positional accuracy of the coil (the pair of coils 61, 62) is improved, fluctuation in vibration characteristics can be reduced.

As shown in fig. 3 and 9, the coil holding portion 42 includes: a cylindrical body portion 422; flange portions 426 to 428; a detour portion 41 having a terminal lead portion 46 and a contact groove portion 47; and engagement projections 44, 45. The flange portions 426 to 428 are disposed at predetermined intervals on the outer peripheral surface of the tubular body portion 422, and protrude radially from the outer peripheral surface.

The coil holding portion 42 is formed in a bobbin shape by a cylindrical body portion 422 and flange portions 426 to 428. The coil holding portion 42 includes coil mounting portions 42b and 42c around which coils (a pair of coils 61 and 62) are wound between the flange portions 426 to 428.

The cylindrical body 422 is cylindrical, is positioned radially inward of the pair of coils 61 and 62, and has an inner peripheral surface 42a facing the outer peripheral surface 20a of the movable body 20 with a predetermined gap (gap G). The inner peripheral surface 42a is flat in the axial direction (vibration direction) so that the gap G is kept at a constant width in the axial direction both when the movable body 20 is not moving and when it is moving, and may be a flat peripheral surface having no irregularities. That is, the gap G is a distance at which the movable body 20 can move so as not to contact the inner peripheral surface 42a when moving in the vibration direction.

The inner peripheral surface 42a is axially flat so as to maintain straight pipe loss against fluid in the entire movable region of the movable body 20 together with the outer peripheral surface 20a of the movable body 20.

The cylindrical body 422 is located between the magnet 21 and the pair of coils 61 and 62, thereby preventing the magnet 21 from contacting the pair of coils 61 and 62. The tubular body 422 guides the movable body 20 so as to reciprocate along the inner peripheral surface 42 a.

That is, the tubular body 422 functions as a protection wall portion that protects the movable body 20 from collision with the pair of coils 61 and 62 during driving of the movable body 20. The thickness of the cylindrical body 422 is a thickness having strength that does not affect any of the pair of coils 61, 62 on the outer periphery side even if the movable body 20 that moves contacts.

The coil attachment portions 42b and 42c are recessed on the outer peripheral surface of the tubular body portion 422.

Specifically, the coil attachment portions 42b and 42c (see fig. 9) are formed by the outer peripheral surface of the tubular body portion 422 and the flange portions 426 to 428, and open radially outward from the outer peripheral surface of the tubular body portion 422.

The coil mounting portions 42b and 42c are provided so as to be partitioned by the flange portions 426 to 428. A pair of coils 61, 62 is wound around the coil mounting portions 42b, 42 c. The pair of coils 61 and 62 is wound between flange portions (also referred to as "end flange portions") 427 and 428 so as to sandwich a central flange portion (hereinafter also referred to as "central flange portion") 426 in the vibration direction.

The coils 61 and 62 in the coil mounting portions 42b and 42c are disposed at positions aligned in the coil axial direction so as to surround the outer peripheral surfaces of the first yoke 23 and the second yoke 25 (the outer peripheral surfaces of a part of the magnet 21, the outer peripheral surfaces of the first yoke 23, and the outer peripheral surfaces of the second yoke 25) of the movable body 20. That is, when not energized, the length in the vibration direction of the pair of coils 61, 62 is longer than the length in the vibration direction of the first yoke 23 and the second yoke 25 sandwiching the magnet 21, and the pair of coils 61, 62 are arranged so as to cover them.

The central flange 426 protrudes radially outward from the outer peripheral surface of the tubular body 422 to form a ring shape, and has an annular outer peripheral portion. A winding portion 41 for winding the wire is provided at a part of the outer peripheral portion of the center flange 426.

In the center flange portion 426, the diameter of the portion other than the terminal lead-out portion 46, that is, the diameter of the outer peripheral portion 426a is shorter than the maximum diameter of the other flange portions (end flange portions 427, 428). That is, the diameter of the outer peripheral surface, which is the end surface of the outer peripheral portion 426a of the center flange 426, is smaller than the diameters of the outer peripheral surfaces of the end flange portions 427 and 428, and is disposed at a position that is retracted from the outer ends of the end flange portions 427 and 428. As shown in fig. 5, 6 and 9, the outer peripheral surface of the center flange 426 and a part of the end flange 427, 428 form a concave portion 420 (described in detail later) into which the outer yoke 50 is fitted. The coil mounting portions 42b, 42c are covered with the outer yoke 50.

The winding portion 41 processes the ends (windings 63) of the coils 61, 62 by the terminal lead-out portion 46 to be connectable to an external device, and the communication groove portion 47 guides the windings 64 of the coils into the coil mounting portions 42b, 42 c. Thus, the coil wire (e.g., the wire 64) is wound around the coil mounting portions 42b and 42c so that the coil holding portion 42 appropriately holds the coils 61 and 62.

The terminal lead-out portion 46 has a terminal bundling portion 43. As shown in fig. 5 and 9, the terminal bundling section 43 bundles the windings 63 connecting the ends of the windings of the pair of coils 61, 62, and functions as a connector wiring section connected to an external device. The terminal bundling unit 43 connects the pair of coils 61, 62 to an external device (a power supply unit such as a drive control unit other than the main body of the vibration actuator) so that electric power can be supplied from the external device to the pair of coils 61, 62.

The terminal bundling portion 43 is a conductive member protruding from the outer peripheral portion of the coil holding portion 42, specifically, the cylindrical body portion 422. The terminal bundling section 43 has a rod-like body for bundling the windings of the coil.

The terminal bundling portion 43 is provided by pressing the base end portion into the terminal extraction portion 46 protruding from the outer peripheral portion of the coil holding portion 42, specifically, the outer peripheral surface of the center flange portion 426 of the coil holding portion 42. The wire turns 63 constituting the end portions of the wire turns of the coils 61, 62 are bundled and connected to the terminal bundling portion 43, and are electrically and reliably joined via a transition groove (filet) 432 formed of solder.

The terminal lead-out portion 46 protrudes from the outer peripheral surface of the central flange portion 426, and is thus provided in the central flange portion 426 so as to have a predetermined length in the radial direction, a thickness in the vibration direction, and a width in the circumferential direction, thereby securing a press-in area of the terminal binding portion 43. The terminal lead-out portion 46 has a width parallel to a tangent line to the outer periphery of the central flange portion 426, and in the present embodiment, the terminal lead-out portion 46 is formed in a rectangular parallelepiped, and the terminal binding portion 43, that is, both end portions of the coils 61 and 62 are provided to protrude from the front end surface thereof.

The terminal lead-out portion 46 ensures a press-in area when the terminal binding portion 43 is fixed by press-in, and therefore, the terminal binding portion 43 can be firmly held, and the terminal binding portion 43 can be stably fixed when assembled to the coil holding portion 42.

The terminal drawing unit 46 draws the end of the coil wire forming the coil (the pair of coils 61 and 62) out of the vibration actuator 1 via the terminal bundling unit 43, and connects the end to the power supply. The terminal lead-out portion 46 is inserted through the outer yoke 50 so that the terminal binding portion 43 is exposed to the outside of the outer yoke 50 and further to the outside of the case 10.

Since the terminal bundling portion 43 is provided in the terminal lead-out portion 46, when the terminal lead-out portion 46 is inserted into the outer yoke 50, even if a load of the outer yoke 50 is applied by the contact of the outer yoke 50, the load can be received by the terminal lead-out portion 46. This can prevent the load from being applied to the terminal binding portion 43 when the outer yoke 50 is attached, prevent the terminal binding portion 43 from being deformed by the applied load, and stably manufacture the vibration actuator. Further, an adhesive portion may be provided on the outer peripheral surface of the flange portions 426 to 428 having the same outer diameter, and the outer yoke 50 may be fixed to each of the flange portions 426 to 428 via the adhesive portion. This can realize a more stable vibration characteristic.

A coil wire 64 for connecting coils (a pair of coils 61 and 62) is inserted into the connecting groove 47. In the contact groove 47 of the present embodiment, the winding direction of the coil wire forming the coil 61 and the coil 62 is reversed so as to be opposite to the upper surface and the lower surface of the contact groove 47.

The communication groove 47 is formed so as to open radially outward in the outer peripheral portion of the center flange 426 and extend through the center flange in the vibration direction. Specifically, the communication groove 47 includes: a bottom wall portion forming a groove-like bottom; and a side wall portion (side wall portion) apart from the terminal bundling portion 43 at the bottom wall portion.

The communication groove 47 is covered with the outer yoke 50 in the center flange 426. The communication groove 47 communicates the coil mounting portions 42b, 42c with each other in the vibration direction inside the outer yoke 50 in the radial direction even in a state of being covered by the outer yoke 50. The contact groove 47 is disposed adjacent to or near the terminal lead-out portion 46.

As shown in fig. 5 and 9, the contact groove 47 is a notch-like portion formed adjacent to the terminal lead-out portion 46 and having an inclined bottom surface between parallel wall surfaces. The slit-shaped portion has a function of locking the winding wire so that the winding wire does not come off when one of the coil 61 and the coil 62 is wound and arranged and then the other is wound and arranged in the opposite winding direction. The communication groove 47 of the present embodiment is formed in a U-shape in plan view, with both end portions spaced apart in the circumferential direction with the bottom wall portion as the bottom surface, and both side wall portions being erected.

Thus, when the coil mounting portions 42b and 42c wind the coil wire in the vertical direction to dispose the pair of coils 61 and 62, the coil wire 64 is reliably engaged with the contact groove portion 47 so as not to be separated from the contact groove portion 47. Thus, the winding wire 64 of the coil is guided from one of the coil mounting portions 42b, 42c to the other through the communication groove 47. This makes it possible to easily assemble the pair of coils 61 and 62 to the coil holding portion 42 by winding the coil of one coil.

Further, the detour portion 41 has a coil guide portion 412 on at least one of the upper surface and the lower surface (surfaces spaced apart in the vibration direction) of the center flange portion 426. The coil guide portion guides the winding wire 63 of the coil from the terminal bundling portion 43 to a position (e.g., a corner portion) of a first turn in a coil winding portion (one of the coil mounting portions 42b, 42 c) of the coil holding portion 42. In the present embodiment, the coil guide portions are formed in steps in the upper and lower surfaces of the center flange portion 426, respectively, at an upper surface portion that adjoins the terminal lead-out portion 46 up to one end in the circumferential direction and extends to the contact groove portion 47, and at a lower surface portion at the terminal lead-out portion 46. The coil guide portion is a step provided on the upper and lower surfaces (surfaces in the vibration direction) of the center flange portion 426, and is formed so as to guide the winding wire of the coil from the terminal bundling portion 43 to the bottom surface side of the coil mounting portions 42b, 42c, that is, the outer peripheral surface side of the cylindrical body portion 422.

The end flange portions 427, 428 are provided at both end portions of the cylindrical body portion 422 that are spaced apart in the axial direction, and constitute upper and lower end portions of the coil holding portion 42.

The end flange portions 427 and 428 (also collectively referred to as "both end flange portions") are provided so as to protrude in the radial direction from the outer periphery of the tubular body portion 422 to both end portions in the vibration direction. The outer peripheral portions of the end flange portions 427, 428 have portions of the same diameter as the outer peripheral portion 426a of the center flange portion 426. In other words, a step having the same surface as the outer surface of the center flange 426 is provided in the opening edge portion on the upper side in the vibration direction of the coil mounting portion 42b formed by the end flange 427 and the opening edge portion on the lower side in the vibration direction of the coil mounting portion 42c formed by the end flange 428.

The step surface of the step is located on the same plane as the outer peripheral surface of the central flange 426, whereby the end flange portions 427, 428 constitute a portion having the same diameter as the outer peripheral portion 426a of the central flange 426.

The stepped surfaces and the outer peripheral surface of the coil holding portion 42 form a concave portion 420 that is recessed and open radially outward. By fitting the outer yoke 50 into the concave portion 420, the outer yoke 50 is disposed so that the outer surface of the outer yoke 50 is flush with the outer surfaces of the end flange portions 427 and 428, except for the coil holding portion 42.

By disposing the outer yoke 50 in the concave portion 420, the outer yoke 50 is positioned so as to surround the pair of coils 61 and 62. The outer yoke 50 is stably fixed to the coil holding portion 42 by abutting against the outer peripheral portion 426a and a portion of the end flange portions 427 and 428 having the same diameter as the outer diameter of the center flange portion 426. Thus, even when the height dimension (length in the vibration direction) of the outer yoke 50 becomes large, it can be stably fixed by the attachment method corresponding thereto.

The end flange portions 427 and 428 are formed in cylindrical shapes that are open in a direction spaced apart from the center flange portion 426, for example, in the up-down direction. The elastic support portions 81 and 82 are fixed to the end portions on the opening side, that is, the upper end portion and the lower end portion, of the end flange portions 427 and 428.

The end flange portions 427, 428 have: a horizontal annular surface extending radially outward from an upper end of the tubular body 422, the opening being opened in the vertical direction; a peripheral surface rising obliquely from an outer edge of the annular surface; and an outer peripheral portion erected parallel to the axial direction from an end portion on the radially outer side of the peripheral surface. The outer peripheral portion, which stands up parallel to the axial direction from the radially outer end portion of the peripheral surface, is a wall portion that defines the opening end portions 427a, 428 a.

The engagement projections 44 and 45 are projecting portions provided so as to project in the vibration direction (up-down direction) from upper and lower end portions of the coil holding portion 42, that is, annular upper and lower opening end portions (also referred to as "opening portions of the coil holding portion 42", respectively) 427a and 428a of the end flange portions 427 and 428.

As shown in fig. 3 and 4, the engagement projections 44 and 45 engage with the engagement recess 127 of the cover 12 of the case 10 and the engagement recess 117 (see fig. 10 and 11) of the case body 11. The engagement projections 44 and 45 engage with the engagement recesses 127 and 117, thereby positioning the coil holding portion 42 and the cover 12 and the case main body 11 in the radial direction and the vibration direction, and also positioning the elastic support portion 81 sandwiched by the engagement projections 44 and the elastic support portion 82 sandwiched by the engagement projections 45 in the radial direction.

The engagement projections 44 and 45 are disposed so as to face the top surface 122 of the lid 12 and the bottom 114 of the case body 11, and the end flange portions 427 and 428 receive the top surface 122 and the bottom 114 with the elastic support portions 81 and 82 interposed therebetween.

The positions of the elastic support portions 81 and 82 with respect to the coil holding portion 42 are found by fitting the engagement projections 44 and 45 into the positioning groove portion 808. Thus, the positions of the elastic support portions 81 and 82 in the respective bodies of the drive unit 15 are set in the same manner, and stable position determination of the elastic support portions 81 and 82 with respect to the coil holding portion 42 can be performed. Thus, the movement of the elastic support portions 81 and 82 in the rotational direction is restricted, and as a product, the deviation of the elastic support portions 81 and 82 can be suppressed, thereby realizing stable characteristics.

A plurality of engagement projections 44 and 45 are provided at equal intervals around the axis of the coil holding portion 42.

The positioning groove 808 of the elastic support portions 81 and 82 is engaged with the engagement projections 44 and 45. This reduces the catching and friction of the elastic support portions 81 and 82 when the movable body 20 is inserted into the coil holding portion 42, and allows easy attachment with good assembling, and easy positioning of the movable body 20 and the coil holding portion 42.

The coil holding portion 42 is accommodated and fixed in the housing in a state of facing the edge portion of the lid portion 12 and the edge portion of the bottom portion 114 by engaging the engaging projections 44, 45 of the upper end portion and the lower end portion with the engaging recesses 127, 117 of the housing 10.

When not driven, the coil holding portion 42 supports the movable body 20 via the elastic support portions 81 and 82 so that both edge portions in the vibration direction of the outer peripheral surface of the movable body 20 protrude in the vibration direction than both edge portions in the vibration direction of the inner peripheral surface 42 a. In addition, during driving, the coil holding portion 42 also supports the movable body 20 so that a gap G of a constant length (width) extending in the vibration direction is formed with respect to the inner peripheral surface 42a of the cylindrical outer peripheral surface 20 of the movable body 20.

< coils 61, 62>

In the vibration actuator 1, the pair of coils 61 and 62, together with the magnet 21, the first yoke 23, and the second yoke 25, constitute a magnetic circuit used for generating a drive source, with the axial direction of the pair of coils 61 and 62 (the magnetization direction of the magnet 21) as the vibration direction.

The pair of coils 61 and 62 is energized during driving (during vibration), and constitutes a voice coil motor together with the magnet 21. In the present embodiment, the pair of coils 61 and 62 is provided, but one coil may be used or three or more coils may be used as long as the coils constitute a magnetic circuit that is driven in the same manner.

The pair of coils 61 and 62 are arranged at positions symmetrical about the magnet 21 in the vibration direction with respect to the movable body 20 including the magnet 21, the first yoke 23, the second yoke 25, and the like. Preferably, the center position of the length in the vibration direction of the coil, that is, the center position of the length between the upper end of the coil 61 and the lower end of the coil 62 is the same position (including substantially the same position) in the vibration direction as the center position of the length in the vibration direction of the movable body 20 (particularly, the magnet 21).

In the present embodiment, the pair of coils 61 and 62 are configured by winding the windings of one coil in opposite directions, and when current is applied, currents flow in opposite directions in the coils 61 and 62, respectively.

The respective ends of the pair of coils 61, 62, that is, both ends of the windings of the coils constituting the pair of coils 61, 62 are tied and connected to the terminal tying portion 43 of the flange portion 426.

The pair of coils 61 and 62 are connected to a power supply unit (for example, a drive control unit 203 shown in fig. 19 and 20) via a terminal bundling unit 43. For example, the respective end portions of the pair of coils 61, 62 are connected to an ac supply unit via a terminal binding unit 43, and an ac power source (ac voltage) is supplied from the ac supply unit to the pair of coils 61, 62. As a result, the pair of coils 61 and 62 can generate thrust force between the coils and the magnets, which can move in directions approaching or separating from each other in the axial direction of the coils.

In the present embodiment, as shown in fig. 9, the pair of coils 61 and 62 are led to a position where the first turn is formed in the coil mounting portion 42b by passing the step in the coil guide portion 412 on the coil mounting portion 42b side on the other end side of the coil wound around the one end of the coil bundled by one of the terminal bundling portions 43. At this first turn position, the wire is wound counterclockwise to form a first turn, which in turn is wound counterclockwise to form a coil 62.

Next, the winding wire on the other end side of the coil 62 is guided to the coil mounting portion 42c through the linking groove portion 47 as described above, and the winding direction is reversed in the linking groove portion 47 so as to be positioned at the first turn of the coil mounting portion 42 c. Thereafter, the coil 61 is formed in the coil mounting portion 42c by winding in the opposite direction to the coil mounting portion 42b, and in the present embodiment, clockwise. In the present embodiment, the coil (the pair of coils 61 and 62) is formed of one wire, but the present invention is not limited to this, and a separate coil (the pair of coils 61 and 62) may be used. In this configuration, when the split coils are configured by winding the coils in the same direction, currents in different directions are supplied during driving.

The coil axes of the pair of coils 61 and 62 are preferably arranged coaxially with the axis of the coil holding portion 42 or the axis of the magnet 21.

In the vibration actuator 1, the pair of coils 61, 62 are formed in a cylindrical shape by winding the coil wire around the coil mounting portions 42b, 42c from the outside of the coil holding portion 42. Thus, the coils 61 and 62 can be assembled without using a self-assembled wire, thereby reducing the cost of the coils (the pair of coils 61 and 62) themselves and further reducing the cost of the entire vibration actuator.

< outer yoke 50>

As shown in fig. 3 to 5, the outer yoke 50 is a cylindrical magnetic body, and is disposed at a position surrounding the outer peripheral surface of the coil holding portion 42 and covering the pair of coils 61 and 62 radially outward.

As described above, the outer yoke 50 forms a magnetic circuit on the fixed body side together with the pair of coils 61 and 62, and forms a magnetic circuit together with the magnetic circuit on the movable body side, that is, the magnet 21, the first yoke 23, and the second yoke 25. The outer yoke 50 prevents leakage of magnetic flux in the magnetic circuit to the outside of the vibration actuator 1.

The outer yoke 50 can increase the thrust constant in the magnetic circuit to improve the electromagnetic conversion efficiency. The outer yoke 50 has a function as a magnetic spring together with the magnet 21 by utilizing the magnetic attraction force of the magnet 21, and can reduce the stress of the elastic support portions 81 and 82 when the elastic support portions 81 and 82 are mechanical springs, and can improve the durability of the elastic support portions 81 and 82.

In the vibration actuator 1, the coils 61 and 62 are energized via the terminal bundling portion 43, so that the coils 61 and 62 cooperate with the magnet 21 and the movable body 20 reciprocates in the vibration direction in the housing 10.

The outer yoke 50 is disposed such that the center of the length of the outer yoke 50 in the vibration direction is at the same height as the center of the magnet 21 disposed inside in the vibration direction. By the shielding effect of the outer yoke 50, the leakage magnetic flux to the outside of the vibration actuator can be reduced.

The two ends of the outer yoke 50 spaced apart in the vibration direction are located at positions lower than the two ends of the movable body 20 in the vibration direction, respectively, when the movable body 20 is movable. That is, the outer yoke 50 has a length in the vibration direction that covers both ends of the movable region in the vibration direction of the laminated body in which the magnet 21, the first yoke 23, and the second yoke 25 are laminated.

The outer yoke 50 has a yoke main body 51 and an opening 53 provided at a central portion in the vibration direction of the yoke main body 51.

The yoke main body 51 is a magnetic body formed in a cylindrical shape, and is formed of, for example, a SECC (electrogalvanized steel sheet) excellent in weldability and corrosion resistance.

In the present embodiment, the yoke main body 51 has flexibility, and a slit parallel to the axial direction is provided in a part of the peripheral wall. The yoke main body 51 is formed in a cylindrical shape having a C-shape when viewed in a horizontal cross section. When the yoke main body 51 is attached to the outer periphery of the coil holding portion 42, the coil holding portion 42 is disposed inside the yoke main body 51 after the end portions 52 constituting the slit portion are widened. Next, the deformation of the yoke main body 51 is restored, and the yoke main body 51 is fitted into the concave portion 420 of the outer periphery of the coil holding portion 42, whereby the yoke main body 51 is externally attached to the coil holding portion 42.

The opening 53 allows wires connecting the external device to the coils 61 and 62 to pass through. Further, the opening 53 is provided to extend in the circumferential direction at the center of the slit portion of the yoke main body 51. An upper edge portion and a lower edge portion of the partition opening 53 are formed in the yoke main body 51 by end portions 52 extending in the circumferential direction to oppose each other in the circumferential direction.

The terminal lead-out portion 46 is inserted into the opening 53. Thus, the terminal bundling portion (wiring portion) 43 connected to the coils 61, 62 is disposed in the opening 53. The terminal binding portion (wiring) 43 is disposed in the driving unit 15 so as to protrude to the outside of the outer yoke 50 and be exposed so as to be connectable to an external device.

The opening 53 is fitted to the terminal lead-out portion 46, and thus functions as a rotation stopper for preventing the outer yoke 50 from rotating circumferentially with respect to the coil holding portion 42.

The outer yoke 50 may be formed so as to sandwich the terminal lead-out portion 46 between right and left sides of the opening 53.

< elastic support portions 81, 82>

The elastic support portions 81 and 82 shown in fig. 3 to 7 support the movable body 20 so that the movable body 20 can reciprocate freely with respect to the fixed body 40 in the vibration direction.

The elastic support portions 81 and 82 sandwich the movable body 20 in the vibration direction of the movable body 20, and are provided so as to intersect the vibration direction in both the movable body 20 and the fixed body 40.

In the present embodiment, as shown in fig. 3 and 7, the elastic support portions 81 and 82 are attached in parallel to each other across each of the two ends (upper end and lower end) of the coil holding portion 42 and the two ends of the movable body, which are spaced apart in the vibration direction.

The elastic support portions 81 and 82 are formed in a circular plate shape, and have a shape in which an annular inner peripheral portion 802, which is an inner spring end, and an annular outer peripheral portion 806, which is an outer spring end, are joined by a deforming arm 804, which is elastically deformed in a planar view.

The deformation arm 804 is arranged in a spiral shape connecting the inner peripheral portion 802 and the outer peripheral portion 806, and the inner peripheral portion 802 and the outer peripheral portion 806 are displaced in the axial direction relative to each other by deformation of the deformation arm 804.

The elastic support portions 81 and 82 support the movable body 20 so that the movable body 20 is free to move in the axial direction (vibration direction) without contacting the fixed body 40.

The elastic support portions 81 and 82 are respectively a plurality of flat plate springs. The movable body 20 is supported by a pair of elastic support portions 81 and 82 as a plurality of elastic support portions, but may be supported by three or more leaf springs. These plurality of leaf springs are mounted in a direction orthogonal to the vibration direction.

When the movable body 20 is driven (vibrated) or even when an external impact is received, the movable body 20 is not in contact with the pair of coils 61 and 62 even when the movable body 20 is in contact with the inner peripheral surface 42a of the tubular body 422, and therefore, the elastic support portions 81 and 82 are not damaged. The elastic support portions 81 and 82 may be any member as long as they elastically support the movable body 20 so that the movable body 20 can freely move. The elastic support portions 81 and 82 are identical members having the same structure in the present embodiment.

The inner peripheral portion 802 has a connection hole 802a arranged at the center of the elastic support portions 81, 82. In the connection hole 802a, both ends of the movable body 20 spaced apart in the vibration direction are connected by fitting. Specifically, the spring fixing portions 274, 294 of the weights 27, 29 are inserted into the inner peripheral portion 802, and the inner peripheral portion 802 is sandwiched by the weights and the flange portions of the spring fixing portions.

On the other hand, the outer peripheral portion 806 is attached to the upper and lower ends of the coil holding portion 42, that is, the open ends 427a, 428a of the end flange portions 427, 428. The outer peripheral portion 806 may be bonded to the open ends 427a, 428a of the end flange portions 427, 428 by an adhesive or the like, and fixed to the open ends 427a, 428a. The outer peripheral portion 806 may be fixed by being sandwiched between the opening end portions 427a, 428a and the positioning step portions 128, 118 on the housing 10 side in a state in which the engagement projections 44, 45 are engaged with the positioning groove portion 808 to be positioned. In the present embodiment, the outer peripheral portion 806 is fixed in a state sandwiched by the open end portions 427a, 428a and the positioning step portions 128, 118 on the housing 10 side.

The leaf springs used for the elastic support portions 81 and 82 may be formed of any material if they are elastically deformable, and may be formed by metal plate processing using stainless steel plates, phosphor bronze, or the like. In the present embodiment, the elastic support portions 81 and 82 are formed as thin flat disc-shaped coil springs made of phosphor bronze having high workability, excellent corrosion resistance, and high tensile strength and wear resistance. In addition, if the magnetic circuit is formed of a nonmagnetic material such as phosphor bronze, the flow of the magnetic flux of the magnetic circuit is not disturbed at all. The elastic support portions 81 and 82 may be formed of resin if the movable body 20 is supported so that the movable body 20 can vibrate. Further, since the elastic support portions 81 and 82 are flat plates, the positional accuracy, that is, the machining accuracy can be improved as compared with a conical spring.

In the present embodiment, the plurality of elastic support portions 81, 82 are joined to the coil holding portion 42 and the movable body 20 in the same direction of the spiral.

In the present embodiment, the elastic support portions 81 and 82 are provided with the damping portions 88 for damping vibrations generated in the elastic support portions 81 and 82 on the deformation arm 804 or the deformation arm 804 and the outer peripheral portion 806.

As described above, in the present embodiment, as the plurality of elastic support portions 81 and 82, a plurality of spiral leaf springs are used in the same spiral direction, and are attached to the two end portions of the movable body 20 spaced apart in the vibration direction, respectively, so as to elastically support the movable body 20 with respect to the fixed body 40.

Thus, when the movement amount of the movable body 20 becomes large, the movable body slightly rotates while moving in the translational direction (for example, the direction on the surface perpendicular to the vibration direction). If the directions of the spirals of the plurality of leaf springs are opposite directions, the plurality of leaf springs move in the buckling direction or the stretching direction to each other, preventing smooth movement.

Since the elastic support portions 81 and 82 of the present embodiment are fixed to the movable body 20 so that the spiral direction is the same, even if the movement amount of the movable body 20 becomes large, the movable body can smoothly move in the vibration direction, that is, deform. This can increase the amplitude and improve the vibration output. However, the spiral directions of the plurality of elastic supporting portions 81 and 82 may be set to be opposite to each other according to a desired movable range of the movable body 20.

The plate-like elastic support portions 81 and 82 are joined to the movable body 20 by fitting the respective inner peripheral portions 802 of the elastic support portions 81 and 82 into the spring fixing portions 274 and 294 constituting the ends of the movable body 20 in the vibration direction. Further, an adhesive or the like may be applied to the spring fixing portions 274 and 294 to join the inner peripheral portion 802. At this time, the spring fixing portions 274 and 294 may be firmly bonded to the inner peripheral portion 802 by an adhesive agent stored in a notch formed in an arc shape around the inner peripheral portion 802.

The outer peripheral portion 806 of the elastic support portion 81 is positioned and fixed at a position avoiding the engagement protrusion 44 on the annular opening end 427a of the end flange 427. On the other hand, the outer peripheral portion 806 of the elastic support portion 82 is positioned and fixed at a position avoiding the engagement protrusion 45 on the annular opening end surface 428a of the end flange portion 428.

In this way, the elastic support portions 81 and 82 are sandwiched between the open end portions 427a and 428a of the upper and lower opening edges of the coil holding portion 42 and the lid 12 and the bottom 114 of the case 10 in a direction perpendicular to the vibration direction.

The elastic support portions 81 and 82 are attached to the coil holding portion 42 and the movable body 20 housed in the coil holding portion 42 so as to close the upper and lower openings of the coil holding portion 42 around which the pair of coils 61 and 62 are wound on the outer peripheral side.

The elastic support portions 81 and 82 are joined to the movable body 20 by pressing the connection holes 802a of the inner peripheral portion 802 against the spring fixing portions 274 and 294 of the weights 27 and 29 at the upper and lower ends of the movable body 20. Then, the positioning groove 808 is engaged with the engagement projections 44 and 45, and the outer peripheral portion 806 is fixed in contact with the open end portions 427a and 428a of the coil holding portion 42. Thus, the drive unit 15, which defines the positional relationship between the coil (the pair of coils 61 and 62) and the movable body 20, is configured to be easily disposed in the housing 10.

< damping portion (shock absorber) 88>

The damping portion 88 is attached to the elastic support portions 81 and 82, suppresses resonance peaks caused by the elastic support portions 81 and 82, and generates stable vibrations over a wide range.

When the movable body 20 supported by the elastic support portions 81 and 82 is disposed in a state where the position of the central axis is deviated in the coil holding portion 42, that is, when the misalignment occurs, it is conceivable that the gap G is narrow and the gap G is not a constant width in the radial direction over the entire circumference of the movable body 20. However, by attaching the damping portions 88 to the elastic support portions 81 and 82, the movable body 20 can be appropriately moved by adjusting the axial offset.

The damping portion 88 is formed in a cross-sectional H-shape having a pair of flanges disposed in parallel and opposite to each other with the elastic support portions 81 and 82 interposed therebetween, and a rib (press-fitting portion) connecting the central portions of the flanges to each other, and is an elastic member such as an elastic body. The damping portion 88 is disposed while being in contact with both the outer peripheral portion 806 and the deformation arm 804 in the present embodiment by inserting an elastic body between the bridge portion of the elastic support portion 81 as a leaf spring. The plurality of attenuation portions 88 are attached to the elastic support portion 81 without being fixed.

The damping portion 88 damps the intense spring resonance in the elastic support portions 81, 82 to prevent the vibration around the resonance frequency from significantly increasing and the frequency-induced vibration from greatly varying.

Thus, even when the movable body 20 vibrates so as to plastically deform the elastic support portions 81 and 82, the movable body 20 can vibrate without contacting the top surface portion 122 and the bottom portion 114 before plastic deformation, and abnormal noise caused by the contact of the movable body 20 with the top surface portion 122 and the bottom portion 114 can be avoided. The damping portion 88 may be formed of any shape, material, or the like as long as it is a member that prevents the occurrence of intense vibration in the elastic support portions 81 and 82.

< Shell 10>

Fig. 10 is a top side perspective view of the case body 11, and fig. 11 is a bottom side perspective view of the cover 12.

As shown in fig. 1 to 3, 10 and 11, the case 10 houses the drive unit 15 by closing the opening 115 of the bottomed tubular case body 11 with the cover 12. The case 10 is formed of resin such as PBT. The case body 11 and the cover 12 may be molded resin such as PBT.

The housing main body 11 has: a tubular peripheral wall portion 112; a bottom 114 closing one opening of the peripheral wall 112; a wire holding portion 18. The peripheral wall portion 112 is provided with a cutout portion 113 having a shape obtained by cutting out the opening 115 side which is the other opening.

The lid 12 and the bottom 114 in the case 10 constitute a top surface 122 and a bottom surface (bottom 114) of the vibration actuator 1 in the present embodiment, and are disposed so as to face the movable body 20 of the drive unit 15 with a predetermined interval therebetween in the vibration direction of the movable body 20. The cover 12 has a hanging portion 124 hanging from a part of the outer periphery of the top surface 122 and engaging with the cutout 113 of the case body 11. Further, since the case 10 is made of resin, the lid 12 is bonded to the case body 11 by welding and pressure-bonding the opening edge of the case body 11. In fig. 10, the opening edge of the case body 11 is shown in a bent shape after crimping.

The cover 12 and the bottom 114 define a maximum movable range of the movable body 20 in the drive unit 15. The top surface 122 of the cover 12 and the back surface of the bottom 114 of the housing body 11 are provided with mortar-shaped (truncated-cone-shaped) recesses 122b, 114b, respectively. The inclined peripheral surfaces of the concave portions 122b, 114b are formed along the deformed state of the elastic supporting portions 81, 82.

The concave portion 122b of the top surface portion 122 and the concave portion 114b of the bottom portion 114 define an internal space between the lid portion 112 and the bottom portion 114, that is, a movement space outside in the vibration direction than the elastic support portions 81 and 82 sandwiching the movable body 20, in the case 10, and prevent plastic deformation of the elastic support portions 81 and 82.

Thus, even when a force exceeding the movable range is applied to the movable body 20, the elastic support portions 81 and 82 are in contact with the fixed body 40 (at least one of the lid 12 and the bottom 114) before plastic deformation. The movable range is wider than the movable region of the movable body 20 in the axial direction (vibration direction).

The recess 122b and the recess 114b define the movable spaces GS1 and GS2 of the movable body 20 and the elastic support portions 81 and 82 by combining the inner spaces of the cover 112 and the bottom 114 with the inner spaces of the end flange portions 427 and 428 of the drive unit 15. The movable spaces GS1, GS2 have a shape that is plane-symmetrical with respect to a cross section perpendicular to the axis passing through a center position in the axial direction. That is, the storage capacities of the fluids in the movable spaces GS1 and GS2 are substantially the same.

The movable spaces GS1 and GS2 are closed spaces, but a hole for canceling the air pressure difference between the inside and the outside of the vibration actuator 1 to minimize the air damping effect due to the pipe resistance may be provided. Such minimum holes may be formed at the joint portions formed by adhesion between the outer peripheral portions 806 of the elastic support portions 81, 82, the coil holding portion 42, and the positioning step portions 128, 118.

The ratio of the volume occupied by the movable body 20 to the entire volume of the inner space including the movable spaces GS1 and GS2 and the inner side of the cylindrical body portion 422 of the fixed body 40 is preferably approximately 50%, and more preferably 50% or more of the entire volume is occupied by the movable body 20.

The movable spaces GS1 and GS2 are connected to both ends of a cylindrical gap G formed between the outer peripheral surface 20a of the movable body 20 and the inner peripheral surface 42a of the coil holding portion 42 and having a constant width over the entire periphery of the outer peripheral surface 20a in the housing 10.

The movable spaces GS1 and GS2 are a pair of fluid storage chambers that communicate with the gap G at both axial ends of the movable body 20 in the fixed body 40, and store air as a fluid.

As shown in fig. 3, the movable spaces GS1 and GS2 are provided so as to be steeply enlarged in diameter relative to the inner peripheral surface 42 a.

Fig. 12 is a partially enlarged sectional view for explaining the gap G and the movable spaces GS1, GS 2.

As shown in fig. 12, the movable space GS1 is formed at a position where the inner peripheral surface on the fixed body side is enlarged in diameter (shown as D1) from the width of the gap G.

Thus, the movable spaces GS1 and GS2 having an outer diameter larger than the gap G are connected to both ends of the cylindrical gap G extending in the axial direction in the housing 10, thereby forming the movable region of the movable body 20. The movable spaces GS1 and GS2 also have radial portions (radial portions of the space S1) longer than the outer diameter D1. The function of the movable spaces GS1 and GS2 during movement of the movable body 20 will be described later together with the gap G.

As shown in fig. 12, a space S1 between the chamfer 276 and the opening (opening end 427 a) of the coil holding portion 42 facing the chamfer 276 radially outward (in a direction orthogonal to the axial direction) is larger than the diameter of the recess 112b of the movable space GS 1. Thus, the space S1 is a space that expands outward from the movable body 20, and when the weight 27 of the movable body 20 moves to the recess 114b side, air existing in the recess 114b can be moved and stored.

When the movable body 20 is not movable, the gap G is smaller than a length S2 of a portion of the outer peripheral surface 20a of the movable body 20 protruding toward the opening from the inner peripheral surface 42a disposed parallel to and facing each other.

As shown in fig. 10, a positioning step 118 is provided on the inner surface side of the bottom 114 so as to protrude from the outer peripheral portion of the recess 114b, and an engagement recess 117 is provided adjacent to the positioning step 118. On the other hand, as shown in fig. 11, a positioning step 128 is provided protruding from the outer peripheral portion of the top surface portion 122 on the back surface side of the top surface portion 122, and an engagement recess 127 is provided adjacent to the positioning step 128.

In the present embodiment, the terminal lead-out portion 46 and the hanging portion 124 of the coil holding portion 42 are disposed in the cutout portion 113 of the housing 10. The terminal lead-out portion 46 is disposed in the center portion of the housing 10 in the cutout portion 113, surrounded by the peripheral wall portion 112 and the sagging portion 124, and closes the cutout portion 113. Thus, the terminal binding portion 43 is disposed in a state protruding outward from the outer peripheral surface of the housing 10, and the vibration actuator 1 is easily connected to an external device via the terminal binding portion 43.

The thickness of the bottom portion 114 and the top portion 122 is formed thicker than the thickness of the peripheral wall portion 112. This makes it possible to sufficiently receive the impact of the movable body or the external member due to the falling or the like. In addition, even if a sudden pressure change occurs in the internal space when the movable body 20 moves, the pressure can be received, and durability can be improved.

< gap G and Movable spaces GS1, GS2>

As shown in fig. 3, in the case 10, the outer peripheral surface 20a of the movable body 20 protrudes to both sides in the axial direction over the entire movable region of the movable body 20 (the movable spaces GS1 and GS2 and the movable body accommodating space including the center of the gap G) and is longer than the inner peripheral surface 42a of the coil holding portion 42. Thus, the gap G is formed between the outer peripheral surface 20a of the movable body 20 and the inner peripheral surface 42a of the coil holding portion 42, and is formed to have a constant width in the axial direction when the movable body 20 is not moved, and is formed to have a constant width in the axial direction when the movable body 20 is moved. The gap G is configured to have the same width as that of the movable body 20 when the movable body is not movable, for example.

That is, the gap G is a cylindrical space, has a length (width) in the radial direction in a uniform length over the entire circumference of the movable body 20 so as to surround the outer circumference of the movable body 20, and has a width of the annular shape so as to extend uniformly in the axial direction (vibration direction).

The line resistance generated in such a gap G is generated by the movable body 20 moving inside the coil holding portion 42, that is, inside the inner peripheral surface 42 a. In the present embodiment, the pipe in which the fluid flows due to the pipe resistance corresponds to a wall surface surrounding the gap G such as the inner peripheral surface 42a of the coil holding portion 42 and the outer peripheral surface 20a of the movable body 20.

Due to the pipe resistance, the movement of air in the movable spaces GS1, GS2 at both ends in the vibration direction of the movable body 20 in the housing 10, that is, the movement of air (fluid) flowing in the movable spaces GS1, GS2 via the gap G is suppressed. The pipe resistance applies air damping to the air over the entire movable region of the movable body in the housing 10, and the air damping effect is exerted, thereby damping the vibration of the movable body 20.

As the line resistance, generally, there are known a straight pipe loss which is a loss of kinetic energy due to friction between a pipe and a fluid, an inlet loss, an outlet loss, a flow shrinkage loss, a stripping flow loss, and the like due to a difference in line shape (a change in flow path shape).

The inlet loss is a loss of kinetic energy generated when the fluid flows into the pipe from a wide area, and in the vibration actuator 1, it can be considered that air flows into the gap G from the movable spaces GS1 and GS 2.

The outlet loss is a loss of kinetic energy generated when the fluid flows out from the pipe to the wide area, and in the vibration actuator 1, it can be considered that the air flows out from the gap G to the movable spaces GS1 and GS 2.

The contraction flow loss (contraction loss) is a loss of kinetic energy generated by contraction of the flow, which is generated by the contraction flow (also referred to as "compressed flow") together with the vortex, when the fluid flows in the pipe having a sharply reduced pipe cross section, and is considered to be a loss generated when air flows into the gap G from the movable spaces GS1 and GS2 in the vibration actuator 1.

The separation flow loss is a loss of kinetic energy generated by the generation of a separation flow together with a vortex without generating a large separation region along the shape, for example, when a fluid flows in a pipe having a pipe cross section that is greatly enlarged. In the vibration actuator 1, it is considered that air is lost when it flows into the movable spaces GS1 and GS2 from the gap G.

The movable body 20 and the fixed body 40, particularly the outer peripheral surface 20a and the inner peripheral surface 42a, are configured in such a manner as to generate a line resistance including a loss of at least one of these kinetic energies.

< thread holding portion 18>

Fig. 13 is a left side view of the vibration actuator for explaining the wire holding portion, fig. 14A and 14B are views for explaining the wire holding portion, fig. 14A is an enlarged perspective view of the wire holding portion, and fig. 14B is a view showing the wire holding portion 18 before the holding of the lead wire 16.

The wire holding portion 18 shown in fig. 1 to 3, 13 and 14 holds the lead wires 16 electrically connected to the coils 61 and 62 of the driving unit 15 housed in the case 10 so as not to apply a load from the outside to the connection portions with the coils 61 and 62.

Specifically, the wire holding portion 18 holds the lead wire 16 which is externally introduced and connected to the windings of the coils 61 and 62 at the terminal bundling portion 43. The wire holding portion 18 is integrally formed with the housing body 11 of the housing 10, and is therefore formed of the same material as the housing body 11, for example, a resin such as PBT.

The wire holding portion 18 protrudes radially outward from a position along an opening edge portion surrounding the notch portion 113 on the outer surface of the case 10.

The wire holding portion 18 is disposed at a position adjacent to the terminal bundling portion 43 of the driving unit 15 in the circumferential direction.

As shown in fig. 14A, the wire holding part 18 includes: a concave wire insertion portion 182 in which the lead wire 16 is inserted and held; a wire fixing portion 184. The wire insertion portion 182 is formed so that the inserted lead wire 16 linearly faces the terminal bundling portion 43 without applying a load.

The wire fixing portion 184 is formed so as to surround the lead wire 16 inserted in the wire insertion portion 182. The wire fixing portion 184 is deformed by welding. That is, as shown in fig. 14B, before the deformation, a concave portion through which the lead 16 can be inserted is formed together with the wire insertion portion 182, the lead 16 is inserted into the concave portion, and the jig J is brought into contact with the concave portion and heated, thereby being deformed and welded, and the lead 16 is held together with the wire insertion portion 182.

Thus, by inserting the lead 16 into the concave portion and heating the wire fixing portion 184, the lead 16 can be easily held.

The wire holding portion 18 holds the lead wire 16 so as to be fixed by welding or so as to at least restrict movement of the lead wire 16 in the radial direction, but is not limited thereto, and may be configured so as to hold the lead wire 16 with an adhesive 187 as shown in fig. 15.

Fig. 15 is a diagram for explaining a modification of the wire holding portion, and shows a wire holding portion 180 provided on the outer surface of the peripheral wall portion 112 of the housing main body 11 in place of the wire holding portion 18. The wire holding portion 180 is a T-shaped wire holding portion 180 protruding from the outer peripheral surface of the peripheral wall portion 112 of the housing main body 11, and has a concave engaging portion 186 opening laterally between the wire holding portion and the outer peripheral surface. The engaging portions 186 are inserted into the concave portions of the two leads 16, respectively, and engage the concave portions.

The wire holding portion 180 is inserted into the hooking portion 186 to be hooked. At this time, the lead 16 extends to the terminal binding portion 43 in a state where the intermediate portion is engaged with the engaging portion 186, and the tip end portion of the lead 16 is connected to the terminal binding portion 43. The wire holding portion 180 and the lead 16 are fixed to the terminal binding portion 43 with an adhesive 187 in a state where the wire holding portion 180 and the lead 16 are in contact with the terminal binding portion 43.

< action of vibration actuator 1 >

The operation of the vibration actuator 1 based on the magnetic circuit structure will be described with reference to fig. 16 to 17. Fig. 16 is a diagram schematically showing a magnetic circuit structure of the vibration actuator. Fig. 17 is a diagram for explaining the operation of the main body of the vibration actuator, and fig. 17A is a diagram showing a vibration state of the movable body at the maximum amplitude position on the top surface side. Fig. 17B is a diagram for explaining the operation of the main body of the vibration actuator, and is a diagram showing a vibration state of the movable body at the maximum amplitude position on the bottom surface side.

The operation of the vibration actuator 1 will be described by taking as an example a case where the magnet 21 is magnetized such that the front surface 21a side on one side (upper side in the present embodiment) in the magnetization direction is an N pole and the back surface 21b side on the other side (lower side in the present embodiment) in the magnetization direction is an S pole.

In the vibration actuator 1, the movable body 20 is considered to correspond to a mass point portion in a vibration model of a spring mass point system, and therefore, when resonance is intense (has a steep peak), the vibration is damped, thereby suppressing the steep peak. By damping the vibration, the resonance is not steep, and the maximum amplitude position (maximum amplitude value) and the maximum displacement of the movable body 20 at the time of resonance do not fluctuate, so that the vibration based on the appropriate stable maximum displacement can be output.

In the vibration actuator 1, the pair of coils 61 and 62 are arranged such that the coil axes are orthogonal to the magnetic fluxes from the first yoke 23 and the second yoke 25 sandwiching the magnet 21 in the vibration direction.

Specifically, when the magnet 21 is not energized, the magnet is not vibrated, and is emitted from the front face 21a side of the magnet 21, and is radiated from the first yoke 23 to the coil 61 side, passes through the outer yoke 50, passes through the coil 62, passes through the second yoke 25, and flows mf of the magnetic flux incident on the magnet 21 from the rear face 21b side.

Therefore, as shown in fig. 16, when energized, lorentz force in the-f direction is generated in the pair of coils 61, 62 according to the fleming's left hand rule due to interaction between the magnetic field of the magnet 21 and the current flowing in the coils (the pair of coils 61, 62).

The lorentz force in the f direction is a direction orthogonal to the direction of the magnetic field and the direction of the current flowing through the coil (pair of coils 61, 62). Since the coil (the pair of coils 61, 62) is fixed to the fixed body 40 (the coil holding portion 42), a force opposing the lorentz force in the-F direction is generated as a thrust in the F direction in the movable body 20 having the magnet 21 according to the rule of action-reaction. Thus, the movable body 20 having the magnet 21 moves in the F direction, that is, toward the lid 12 (the top surface 122 of the lid 12) (see fig. 17A).

When the pair of coils 61 and 62 is energized by switching the energizing direction of the pair of coils 61 and 62 to the opposite direction, lorentz force in the f direction of the opposite direction is generated (see fig. 16). Since the lorentz force in the F direction is generated, a force opposite to the lorentz force in the F direction is generated in the movable body 20 as a thrust force (-thrust force in the F direction) according to the rule of action-reaction, and the movable body 20 moves in the-F direction, that is, the bottom 114 side of the housing main body 11 (see fig. 17B).

In the vibration actuator 1, when not vibrating without power being applied, the magnetic attractive force acts between the magnet 21 and the outer yoke 50, and functions as a moving magnetic spring. The movable body 20 returns to its original position due to the magnetic attraction force generated between the magnet 21 and the outer yoke 50 and the restoring force of the elastic support portions 81 and 82 to return to its original shape.

The vibration actuator 1 is driven by an ac wave input from a power supply unit (for example, a drive control unit 203 shown in fig. 19 and 20) to the pair of coils 61 and 62. That is, the direction of energization of the pair of coils 61 and 62 is periodically switched, and in the movable body 20, as shown in fig. 16, thrust in the F direction on the top surface portion 122 side and thrust in the-F direction on the bottom portion 114 side of the lid portion 12 alternately act. Thereby, the movable body 20 vibrates in the vibration direction.

As shown in the SK portion of fig. 17A and 17B, two edge portions of the inner peripheral surface 42a (a portion having a flat cross section) of the coil holding portion 42, which are spaced apart in the vibration direction, are not opposed to the chamfer portions 276, 296 radially outward even when both sides of the movable body 20 in the vibration direction are located at the maximum amplitude positions. The chamfered portions 276, 296 are located outside the inner peripheral surface 42a, and the inner peripheral surface 42a faces the flat outer peripheral surface 20a of the movable body 20.

By the movement of the movable body 20, the air flows in the direction opposite to the movement direction in the gap G, and the pipe resistance is generated to the air. This can increase the air damping in the case 10 while generating pressure loss in the air in the gap G, thereby attenuating the vibration of the movable body 20, and appropriately generating the vibration of the movable body 20.

Accordingly, vibration of the movable body 20 can be suitably damped without providing a vent hole in the housing 10 and without increasing the weight of the movable body 20.

In this way, in the vibration actuator 1, the movable body 20 can be made to vibrate appropriately by damping the vibration of the movable body 20 due to the pressure loss caused by the air flowing in the gap G by the movement of the movable body 20.

Fig. 18 is a diagram for explaining air damping in the vibration actuator 1 of the present embodiment.

Fig. 18 is a diagram showing the resonance frequency of the movable body 20, and the resonance frequency f0 is compared between the vibration actuator 1 that performs air damping and an actuator that is provided with a vent hole or the like without performing air damping, for example. Accordingly, according to the vibration actuator 1 in which the air damping is performed, only the G value (K1) of the peak of the resonance frequency f0 can be suppressed. Accordingly, the vibration actuator 1 can raise the G value of the entire other than the resonance frequency f0 by applying the voltage having the same peak value of the frequency, and can generate appropriate vibration in a wider frequency band.

In this way, according to the vibration actuator 1, the flow of the fluid in the direction opposite to the moving direction of the movable body 20 is generated in the gap G, and the line resistance is generated to the fluid (for example, air). By imparting air damping to the vibration by the line resistance to the air, the vibration can be widened. According to the vibration actuator 1, it is possible to generate an appropriate vibration output in a wide frequency band in accordance with the environment or the like in which the vibration actuator is used while achieving miniaturization.

The outer peripheral surface 20a of the movable body 20 has a length protruding axially to both sides of the inner peripheral surface of the tubular body portion (body portion) 422 of the coil holding portion 42 over the entire movable region of the movable body 20. This can maintain the occurrence of the line resistance, which is an air damping effect, in the entire movable region.

The outer peripheral surface 20a of the movable body 20 and the inner peripheral surface 42a of the tubular main body 422 are respectively flat in the axial direction so that the gap G is a constant width in the axial direction when the movable body 20 is not moving and is kept constant in the axial direction when the movable body 20 is moving, and the generation of straight pipe loss with respect to air is kept throughout the movable region. This can stabilize the air damping.

The fixed body 40 has a pair of movable spaces (fluid storage chambers) GS1, GS2 communicating with the gap G at both ends in the axial direction. The pair of movable spaces GS1, GS2 is formed so as to have a steep diameter expansion with respect to the inner peripheral surface 42a at the inlet and outlet of the gap G, so that loss due to the change in the flow path shape occurs in the entire movable region of the movable body 20, and therefore, the air damping effect can be ensured in the entire movable region. Further, since the movable spaces GS1 and GS2 have a shape that is plane-symmetrical with respect to a cross section perpendicular to the axis passing through the center position in the axial direction, the reciprocating movement of air can be symmetrical, and the air damping effect can be stabilized.

Next, the driving principle of the vibration actuator 1 will be briefly described. In the vibration actuator 1 of the present embodiment, the mass of the movable body 20 is m [ kg ]]The spring constant of the springs (elastic supporting parts 81 and 82 as springs) is K _sp In the case of (2), the movable body 20 has a resonance frequency F calculated by the following equation (1) with respect to the fixed body 40 _r [Hz]And (5) vibrating.

It is considered that the movable body 20 constitutes a mass point portion in the vibration model of the spring mass point system, and therefore, when the resonance frequency F with the movable body 20 is input to the coil (the pair of coils 61, 62) _r When alternating current waves of equal frequency are generated, the movable body 20 is brought into a resonance state. That is, the resonance frequency F with the movable body 20 is input to the coil (the pair of coils 61 and 62) from the power supply unit _r By using ac waves of substantially equal frequency, the movable body 20 can be vibrated efficiently.

The following shows a motion equation and a circuit equation representing the driving principle of the vibration actuator 1. The vibration actuator 1 is driven based on a motion equation shown in the following formula (2) and a circuit equation shown in the following formula (3).

m: quality (kg)

x (t): displacement [ m ]

K _f : thrust constant [ N/A ]]

i (t): current [ A ]

K _sp : spring constant [ N/m ]]

D: damping coefficient [ N/(m/s) ]

e (t): voltage [ V ]

R: resistor [ omega ]

L: inductance (H)

K _e : back emf constant [ V/(rad/s)]

That is, the mass m [ kg ] in the vibration actuator 1 can be appropriately changed within the range satisfying the formula (2)]Displacement x (t) [ m ]]Constant of thrust K _f [N/A]Current i (t) [ A ]]Spring constant K _sp [N/m]Damping coefficient D [ N/(m/s)]Etc. In addition, the voltage e (t) [ V ] can be appropriately changed within a range satisfying the formula (3)]Resistance R [ omega ]]Inductance L [ H ]]Back electromotive force constant K _e [V/(rad/s)]。

In this way, in the vibration actuator 1, the resonance frequency F is used _r When the corresponding ac wave is energized to the coils 61, 62, a large vibration output can be efficiently obtained, and the resonance frequency F _r From the mass m of the movable body 20 and the spring constant K of the elastic support portions 81, 82 as leaf springs _sp And (5) determining.

The vibration actuator 1 is driven by a resonance phenomenon that satisfies the formulas (2) and (3) and uses the resonance frequency shown in the formula (1). As a result, the vibration actuator 1 can be driven with low power consumption, that is, the movable body 20 can be linearly reciprocated with low power consumption. In addition, if the damping coefficient D is increased, vibration can be generated in a high frequency band.

According to the present embodiment, plate-like elastic support portions 81 and 82 are disposed in the up-down (vibration direction) of the movable body 20. As a result, in the vibration actuator 1, the movable body 20 can be stably driven in the vertical direction, and the magnetic fluxes of the pair of coils 61 and 62 can be efficiently distributed from the upper and lower elastic support portions 81 and 82 of the magnet 21. Thus, as the vibration actuator 1, high-output vibration can be realized.

The vibration actuator 1 is configured to have a gap G, and the gap G (specifically, the width (radial length) of the gap G) is set so as to satisfy the following expression (4).

Δp: pressure loss (air damping) [ Pa ]

Lambda: coefficient of friction of pipe

Li: length of tube [ m ]

h: air gap [ m ]

ρ: density of fluid [ kg/m ] ³ ]

u: flow Rate [ m/s ]

The tube in the above equation corresponds to the inner peripheral surface 42a and the outer peripheral surface 20a of the gap G. Pressure loss ΔP [ Pa ]]The phenomenon is that when the fluid flows between the inner peripheral surface 42a of the coil holding portion 42 and the outer peripheral surface of the movable body 20, the flow is subjected to a decrease in resistance pressure due to friction with the wall surface and the wall surface shape. The coefficient of friction λ of the tube (coefficient of friction of the members (inner peripheral surface 42a, outer peripheral surface 20 a) surrounding the gap G) and the length Li [ m ] of the tube (length in the vibration direction of the members (inner peripheral surface 42a, outer peripheral surface 20 a) surrounding the gap G) can be appropriately changed within the range satisfying the formula (4)]An air gap (length of the gap G in the radial direction) h [ m]Density ρ [ kg/m ] of fluid (air) ³ ]Flow velocity u [ m/s ]]Etc. In particular if the length Li in the vibration direction of the gap G is lengthened, the air gap h is narrowerShortening the length of the gap G in the radial direction can increase the pressure loss, i.e., air damping. For example, a predetermined threshold may be set for Li/h, and the gap G may be set to satisfy the expression.

(electronic device)

Fig. 19 and 20 are diagrams showing an example of the mounting form of the vibration actuator 1. Fig. 19 shows an example in which the vibration actuator 1 is mounted on the game controller GC, and fig. 19 shows an example in which the vibration actuator 1 is mounted on the mobile terminal M.

The game controller GC is connected to the game machine main body by wireless communication, for example, and is used by being held or held by a user. In fig. 19, the game controller GC has a rectangular plate shape, and is configured to be operated by a user grasping the left and right sides of the game controller GC with both hands.

The game controller GC notifies the user of an instruction from the game machine main body by vibration. Although not shown, the game controller GC includes functions other than instruction notification, for example, an input operation unit to the game machine main body.

The mobile terminal M is a mobile communication terminal such as a mobile phone or a smart phone. The mobile terminal M notifies the user of an incoming call from an external communication device by vibration, and realizes functions (for example, functions giving an operational feeling, a sense of realism) of the mobile terminal M.

As shown in fig. 19 and 20, the game controller GC and the mobile terminal M each have a communication unit 201, a processing unit 202, a drive control unit 203, and vibration actuators 204, 205, 206 serving as vibration actuators 1 serving as drive units. Further, a plurality of vibration actuators 204, 205 are mounted in the game controller GC.

In the game controller GC and the mobile terminal M, the vibration actuators 204 to 206 are preferably attached such that, for example, the main surface of the terminal and the surface of the vibration actuators 204 to 206 orthogonal to the vibration direction are parallel to each other, in this case, the bottom surface of the base 114.

The main surface of the terminal is a surface that contacts the surface of the user, and in this embodiment, the main surface is a vibration transmission surface that contacts the surface of the user and transmits vibration. The main surface of the terminal may be disposed so as to be orthogonal to the bottom surface of the bottom 114 of the vibration actuators 204, 205, 206.

Specifically, in the game controller GC, the vibration actuators 204 and 205 are attached so that the surfaces of the finger tips, finger pads, leg pads, and the like of the user who performs the operation or the surfaces on which the operation portions are provided are orthogonal to the vibration direction. In the case of the mobile terminal M, the vibration actuator 206 is mounted so that the vibration direction is orthogonal to the display screen (touch panel surface). Thereby, vibrations in a direction perpendicular to the main surfaces of the game controller GC and the mobile terminal M are transmitted to the user.

The communication unit 201 is connected to an external communication device by wireless communication, receives a signal from the communication device, and outputs the signal to the processing unit 202. In the case of the game controller GC, the external communication device is a game machine main body as an information communication terminal, and performs communication in accordance with a short-range wireless communication standard such as Bluetooth (registered trademark). In the case of the mobile terminal M, the external communication device is, for example, a base station, and performs communication in accordance with the mobile communication standard.

The processing unit 202 converts the input signal into a drive signal for driving the vibration actuators 204, 205, and 206 by a conversion circuit unit (not shown), and outputs the drive signal to the drive control unit 203. In the mobile terminal M, the processing unit 202 generates a driving signal based on signals input from various functional units (not shown, for example, an operation unit such as a touch panel) in addition to signals input from the communication unit 201.

The drive control unit 203 is connected to the vibration actuators 204, 205, 206, and a circuit for driving the vibration actuators 204, 205, 206 is mounted. The drive control unit 203 supplies drive signals to the vibration actuators 204, 205, 206.

The vibration actuators 204, 205, 206 are driven in accordance with a drive signal from the drive control section 203. Specifically, in the vibration actuators 204, 205, 206, the movable body 20 vibrates in a direction perpendicular to the main surfaces of the game controller GC and the mobile terminal M.

The movable body 20 may be configured to contact the top surface 122 or the bottom 114 of the cover 12 via a damper each time vibration is performed. In this case, the impact to the top surface 122 or the bottom 114 of the lid 12, that is, the impact to the housing, accompanied by the vibration of the movable body 20 is directly transmitted to the user as the vibration.

Since vibration in a direction perpendicular to the surface of the body is transmitted to the surface of the user in contact with the game controller GC or the mobile terminal M, sufficient bodily-feeling vibration can be imparted to the user. In the game controller GC, body-feeling vibration to the user can be imparted by one or both of the vibration actuators 204 and 205, and high-expressive vibration such as at least strong and weak vibration can be imparted selectively.

The present invention completed by the present inventors has been specifically described based on the embodiments, but the present invention is not limited to the above embodiments and can be modified within a range not departing from the gist thereof.

The vibration actuator of the present invention may be mounted on a contact portion with a user, such as a mobile device (e.g., a mobile information terminal such as a tablet PC or a portable game terminal) other than the game controller GC and the mobile terminal M.

That is, the vibration actuator 1 may be mounted on a contact portion that contacts a user in a hand-held electric device such as an electric cosmetic appliance such as a mobile terminal or a cosmetic massager. The vibration actuator 1 may be mounted on a contact portion that contacts a user in a wearable terminal that is worn by the user. The contact portion that contacts the user is, for example, a grip portion that the user holds when using, for example, in the case of a hand-held electric device such as a game controller GC, and is, for example, a pressing portion that presses the surface of the user's body in the case of a wearable electric device such as a beauty massager.

Industrial applicability

The vibration actuator of the present invention can be miniaturized and can generate an appropriate vibration output in a wide frequency band according to the environment or the like used, and is useful as a device mounted on an electronic device such as a game machine terminal or a mobile terminal, or an electric device such as an electric cosmetic instrument.

Claims

1. A vibration actuator, comprising:

a movable body having a columnar magnet; and

2. The vibration actuator of claim 1 wherein,

the outer peripheral surface of the movable body has a length protruding to both sides in the axial direction beyond the inner peripheral surface of the main body portion in the entire movable region of the movable body.

3. The vibration actuator of claim 2 wherein,

the movable body has the magnet at a central portion in the axial direction, a pair of weights at both end portions in the axial direction, and a pair of yokes respectively located between the magnet and each of the weights,

the magnet, the pair of yokes, and the pair of hammers are formed in cylindrical shapes of the same diameter, respectively, and are joined in the axial direction so that the outer peripheral surfaces of the magnets and the yokes are flush with each other.

4. A vibration actuator according to claim 3, wherein,

an accumulation portion for accumulating an adhesive or a welding material is provided at a joint portion between each of the pair of yokes and the magnet or at a joint portion between each of the pair of weights and each of the pair of weights.

5. The vibration actuator of claim 2 wherein,

the outer peripheral surface of the movable body and the inner peripheral surface of the main body portion are both flat in the axial direction so that the width of the gap in the axial direction is constant when the movable body is not moved, and the gap is kept constant in the axial direction when the movable body is moved, and the generation of straight pipe loss for the fluid is maintained throughout the movable region.

6. The vibration actuator of claim 2 wherein,

the fixed body has a pair of fluid receiving chambers communicating with the gap at both end portions in the axial direction,

the pair of fluid storage chambers is expanded in diameter so as to be steep with respect to the inner peripheral surface, so that loss due to a change in the flow path shape, which occurs at the inlet and outlet of the gap, occurs over the entire movable region of the movable body.

7. The vibration actuator of claim 6 wherein,

the pair of fluid storage chambers are a pair of closed spaces having a shape that is plane-symmetrical with respect to a cross section perpendicular to the axis passing through the center position in the axial direction.

8. An electrical device, either hand-held or wearable, characterized in that,

a structure in which the vibration actuator according to any one of claims 1 to 7 is mounted on a contact portion which is contacted by a user.